Internal combustion or explosion four-stroke-cycle engine



' Dec. 14, 1.926.

fs. G. LINDEQUIST- INTERNAL GOMBUSTIO OR EXPLOSION FOUR-STROKE CYCLE ENGINE Filed May 12, 192s y 50 the compressor space,

Patented Dec. 14, 1926. A.

AUlaii'rufzu STATES APME-isl'r OFFICE.

SVEN GUSTAF LINDEQUIST, OF BERLIN, GERMANY.

INTERNAL 'ooMBUsrIoN on EXrLosroN'FoUnfsTRoxn-GYCLE'ENGINE.

Application lediMay 12, 1923. Serial No. 638,503, and in Germany November A2li, 1922.

This invention relates to .an internal com bustionor explosion four stroke cycle engine in which the compressed air or a compressed mixture ot gas and air is supplied to the.`

5 working space of the cylinder.

Separate compressors or crank case compressors have ybeen used hithertofor compressing thc scavenging air and the air for combustion wherefrom results however an increase ot weight of the total aggregrate. The pressures which can be produced with these compressors are however not sufficient 'to supply to the en I'ne a suicient quantity of -compressed gas i the engine is working at high speed and it consequently the velocity of flow in the gas conduits is great', wheret'rom results for instance that the number ot revolutions of the engine and the efliciency of the same could not be increased to the desired degree. y

According to this invention these inconveniences are avoided by using the space ot the working cylinder which is closed at both ends as compressor chamber which is connected with the working space of the same cylinder or of another cylinder so that the compressed air produced in the compressor chamberof the engine cylinder can get directly into the corresponding working space.

.By this arrangement any loss from separation is avoided, such loss occurring with the compressors of known type. As the ef'riciency of the compressor according to the invention increases with the number of revolutions ot the engine a constant compression is ensured at all speeds. The mixture 1s well heated preliminarily as the compression is eliected in the engine cylinder so that it is possible to use heavy fuels .and oils which could not be used hitherto. On the other hand the cylinder is well cooled by the mlX- ture which is sucked in if the second end ot the cylinder is used as'c'ompressor," this being of considerable advantage, specially for high-speed engines working with overchage.

n adjustable return connection is prefer ably arranged between the connecting pipe,

` shut ott from the compressor space'and from the working space by means of valves, and this return connection consisting ot a second pipe, the cross section of passage of which may be throttled more or less by means of the regulating element.

' It there are several cylinders in one enalways gine two of these cylinders could further be connected the one with the other by means of pipes leading across a multiple way` cock in f such a manner that the two compressor spaces communicate always with one of the working spaces. At tlilsworking method as well as in the case that the compression space of an` engine cylinder works together withA its own working space a quantity ot' compression air, equal to the double volume of the cylinder will be always. at disposal for each lworking stroke of. the four stroke cyclel engine. At the working method laccording to which two compressor spaces communicate with one working space it is not necessary to accumulate one of the cylinder charges, as must be donc if the compression .space works together only with its ownV working space` as charges of compression air from both cylinders are directly transferred to the working cylinder after they have been produced. The reductions ot pressure due to the accumulation, which have a detrimental reaction on'the engine, are thus-avoided.

Reversing valves may be inserted in the suction piping and in the pressure piping for the compressor and auxiliary pipings may be arranged in the engine in such a manner that, according to the position of the valves, the suction pipe from the Carburettor is connected with the suction pipe ot the compressor and the pressure pipe of the compressor with the supply pipe for the workingr space,

or the atmosphere is connected with the suction pipe of the compressor, the suction pipo of the Carburettor with the supply pipe ot theworking space and the pressure pipe ot the compressor with a reservoir for compressed air. VViththis object in vi'ew the case ot one ot the valves which are constructed like four-way cocks, may be connected with the suction pipe of the compressor. the atmosphere. the suction pipe of the Carburettor and a by-pass pipe leading to the second valve,the case oi the second vali'e beinghowever connected with' thebypass pipe, the supply the'reservoir for the compressed air and the pressure pipe of the compressor.

With a construction ot this type it is possible to let the engine work temporarily as sucking in engine that is to say without compressed mixture. and touse the compressor side of the engine during this time for pipe for theworking space.

lila" inlet or suction valve 15 an a means to attain in a simple manner num-J .i bers of revolutions whlch up to the present 4could never be attalned.

An' embodiment of the invention is shown by way of example on the accompanying drawing which illustrates diagrammatically the .construction and gear of a four-cylinder engine. i v

In the cylinders 1, 2, 3, 4 the working pistons 5, 6, 7, 8 are arranged as usual. Every two pistons, -in the form of construction i. shown the pistons 5 and 7 and the pistons 6 and 8, are rigidly connected the one with the other by piston rods 9, 10. The piston rods are shown on the drawing at an exaggerated length in order to make the diagrammatical illustration clearer.' With each piston rod a connecting rod is connected, which is not shown in the drawing, and designed to translate the reciprocating motion into a rotating motion by acting upon a crank shaft.

The working space of the cylinders has, as usual, a sparking plug 1 1, an inletv valve 12 and an outlet valve 13, said valves being controlledin the well known manner by means of cam shafts 14.

vThe other side of the cylinder is closed also and the piston rod is guided by a stuiiing boX. This other end of the cylinder has an an outlet or pressure valve 16. These valves may be constructed as non-return valves if the engine has to work at slow speed, or for high-speed engines they may be controlled by cam shafts, for instance bythe camshafts 14. These valves must be controlled evidently by other cams than the valves for the working cylinder. The construction of such cams being well known they have been indicated on the drawing only diagrammatically. From the compressor space a suction pipe' 17, leads across the suction valve 15 to the fourway reversing valve 18. The case of the four-way reversing valve is connected with the pipe 19 communicating with the atmos-l phere,'the suction pipe20 of the Carburettor and afourth pipe 21 which is connected on the other hand'with a second reversing valve which will be' hereinafter described. y

From the compressor space a pressure pipa 22 conducts'across the pressure valve 16 lto a case 23 and this pressure `pipe 22 is conwith the cylinder 1, Viz if cylinder 2 is considered to be theone described lirst, to the compressor space of 'the cylinder 3.

In the case 23 a multipledvay cock is arranged by means of which'this case is either connected with the pipe 28 leading to the working space of the cylinder 2, as is shown on the drawing, or with the pipe 29 which leads to the working space oi the cylinder 3.

Ifthe multiple-way cock 26 is in the posi-r tion shown on the drawing the mixture com- 'pressed in the cylinders 2and 3 is conducted into the working space of the cylinder 2. `If however the multiple-way cock 26 is rotated in counter-clockwise' direction of 90 the reservoir is made to-communicate with pipe 29 so that the mixture compressed in the two cylinders is conducted into the working space ofthe cylinder 3. Four-way cocks 30 and 31 are'inserted in the pipes 28 -and 29. If the four-way cocks are in the position shown on the drawing the passage through the pipes 28 and 29 is free. It these fourway cocks are however rotated of 45, as shown in the pipes belonging to the cylinders 1 and 4, the plugs of the same interrupt the connection between the parts 28 and 28b respectively 29a and 29b of the pipes 28 and 29, but they establish the connection between the supply pipe 28b of the working cylinder and the intermediate pipe 21 and the pressure pipe 28 with a pipe 32 conducting to a reservoir 33 for compressed air. In a similar manner the cock plug 31 connects the supply pipe 29b of the working cylinder with the intermediate pipe 21 and the pressure pipe 29a with a pipe 34 for compressed air which leads to the air reservoir 33.

Simultaneously with the cock plugs 3C, 31 the correspond-ing cock plugs 18 for the cylinders 1 and 3 have been rotated of 45 so that these coclrplugs connect now the suction pipe 17 with the pipe 19 communil eating with the atmosphere and the intermediate-pr by-pass tube 21 with thehsuc-V tion pipe 20 of the Carburettor.

In order to' ensure the simult-aneousness ofy the reversing the valves `18, 3() and 31 belonging to one pair of cylinders, `for i11- stance to the cylinders 1 and 4 and 2 and 3 respectively are lconnected with the common control mechanism so thatV their position' is simultaneously alteredl by the operation of this control mechanism. The valves 25 of each pair of cylinders'may be connected' -with a common control mechanism in a similar manner. v

While the valves 18, 25, 30 and 31 are operated by hand the valves 26 are operated automatically'from the engine, for instance through the intermediary of the cam shaft,

in such a manner that at the working stroke of one of the cylinders the compression spaces lof the cylinders of one pair of cylinders are connected with theworking space -of the corresponding cylinder. The operation of the device is as follows: Suppose that in the working space of 'the cylinder 3 the air be compressed so that the explosion stroke begins. At this explosion stroke the piston 7 compresses the mixture which has been sucked in by the suction pipe 20 of the Carburettor and by the pipe 17 through the suction valve 15 andthe cylinder forces 4this mixture through `the pressure valve 16 into the pipe 27 and through this pipe into the 2U case 23. From this case 23 the mixture flows into the channel of the cock plug 26 and lfrom there through the pipe 28 and through the inlet valve 12 into the working space of the cylinder 2; At the same time, with the piston 7 of the cylinder 3 at the suction stroke, iston 6 of the cylinder 2 hasy been moved ownward by the crank shaft which is not shown so that this piston compresses also the mixture in front of it andforces the 3U same to liow through the pressure valve 16 into the pipe 22 and lfrom this pipe into the case 23 through the cock plu 26 and through the pipe 28 into the wor 'ng space' of the ycylinder 2.

At the position ofthe valves 25 of the cylinders 2 and 3 as shownl onthe drawing, art of the mixture of as and air flows back into the cylinders at the succeedin suction stroke 'so that in the `pipes 28 an 29 does 40not exist the full pressure which wouldy be produced if the valves 25 were closed. After -the piston 7 has completed the, explosion stroke and the piston 6 the suction stroke the valves 26 are reversed automatically so lthat they connect the compression spaces of the two cylinders 2. 3 with thev working space' of the cylinder 3. ,i t

At the back movement of the pistons 6 and 7 the burnt'oases in c linder 3 are scavenged and in cylinder 2 tie fresh gases are compressed. lInto both compression spaces a fresh mixture of gas and air is however sucked in through the suction valves 15. At the succeeding stroke the fresh mixture is forced intothe working space of cylinder 3 while in cylinder 2 the explosion takes place. In the compression spaces of the two cylinders the previously sucked in mixture of gas and air is compressed and transmitted, as

already mentioned, to the cylinder 3. At the position of the valves shown with regard to the cylinders 1 and 4, the cylinders suck, `at the suction strokfe,rthe asy and air mixture in directly fromthe car 'urettor through the pipes 28", 21 and 20,;the compression spaces .and pipe 34 or from cylinder 3 t mosphere through the pipes19 and 17. The 4 air compressed in the compression spaces is transmitted to the reservoir 33 through the pipes 22 across the case 23, througlh pipe 29L rough the pipe 27, pipe 29a and pipe 34, said air being accumulated in the reservoir 33 forany desired purposes.

In one and four cylinders, eight cylinders or any multiple' number of four cylinders could be used. As stated above the increase of pressure of the mixture of gas and air produced by the arrangement according to the invention has to serve .essentially to ensure the required4 speed at a highl number` of revolutiors'and to enable that owing to the increase of the velocity of the gas the dimensions of the valves and the stroke of the valves may be reduced.` v'This reduction of the dimensions of the valves serves to makel it `possible to increase again the Anumber of revolutions.

Only` in the secondI place the compressor,

serves to increase occasionally the average explosion pressurevin the Worklng cylinder.

, ln order ,toensure a perfect working ofthe compressor the controllingmeans, e. lg. the cams, for the'outlet valve of' the compressor andfor the inlet valve of the work..

ing cylinder, are adjusted with regardto -oneanother and in consideration of the different lengths of the ypipes of the several cylinders which conductv the mixture between `the compresserl outlet andthe working cylinder inlet` yand in consideration of the different resistances in these pipes, inA such amanner that the points of the pulsations of pressure iin the pipes reach always the working cylinder.l at the, moment, when the inlet valve of the working cylinder is being' opened. rlhev height of pressure'must evidently ,correspond with the over-pressure which ,still existsin the working cylinder. v.This,ht-iight,ofprese sure is regulated, as stated above, by vadjusting the by-pass valve 2,5. AIn order to inlllr ence bythis adjusting of the ley-pass valve,

as little as possible the pulsations ofpressure andthe propagation o., the same care has to. be taken that the back flow of the mixture of gas and air takes place from the pressure channel into the compressor as ymuch as pose sible at the beginning of the pressure channel. With 'thisy object in view the return channel 24 could fit into the pressure channel 22 near the beginning of .the same'or, in

order to produce a back-flow, the outlet valve of the compressor would not be completely the same engine, instead of closed, the width of the gap which remains at the extreme closing position of the -pressure valve belng regulated 1n accordance `with the backow desired.V i

I claim 1. In an internal combustionengindfa cylinder closed at bothvends, a piston in said said compression chamber and said cylinder, the space at one end of said piston 2. Infan internal combustion' engine, a cyl-l inder closed at both ends, a piston in said cylinder, the space at one end of said piston serving as combustion chamber and the space at the other end of said piston serving as 'compression chamber, a passage connecting said chambers, aby-pass between said compression chamberrand said passageoperable as pressure releasing means for said passage on the return stroke of said piston, and a control valve in said by-pass.

3. In an internal combustion engine, a plurality of closed cylinders, 'a piston in each cylinder, the space at one end of a piscylinder, the space at one en ton serving as combustion chamber and the space at the other end of said piston serving as compression chamber, and means for putting the combustionv chamber of one of said cylinders in communication with the compression chambers ofaplurality of said cylinders. l

4. In a four cycle internal combustion engine, a plurality of closed cylinders, a piston in each cylinder, the s ace at one end of a piston serving as com ustion chamber and the space at the other end of said piston serving as Acompression chamber, and means for putting the combustion chamber of one of said cylinders incommunication with the compression chambers of a plurality o-said cylinders. i

5. In an internal combustion engine, a

vplurality of closed cylinders, a piston in each cylinder, the space at one end of a piston serving as combustion chamber and the space at the other end of said piston serving s compression chamber, and external pipes connectingthe combustion chamber of one otl said cylinders, without the intervention of a reservoir, with the compression chambers ot' a plurality of said cylinders.

6. In an internal combustion engine, a plurality of closed cylinders, a piston in each cylinder, the space at one end of a piston serving as combustion chamber and the space at the othei` end of said piston serving as compression chamber, communicating means between the combustion chamber of one cylinder andthe com ression chambers of a plurality of said cy inders, and a bypass between said communicating means and a compression chamber.

7. In an internal combustion engine, a plurality of closedcylinders, a iston in each of a piston serving as combustion chamber andthe space at the other end of said piston serving as ,piston in each of said cy inders, the space at one end of a piston serving as combustion' chamber and the space at-the other end of said piston serving as compression chamber, and means for putting in communicatidn the compression chambers of the cylinders ofonel of said groups with the combustion chamber of one of the cylinders of the same group. a

9. In an internal combustion engine, a plurality of closed cylinders arranged in coacting groups of two opposed cylinders, a piston ineach of said cylinders, the space at one end of a. piston serving ascombustion.

chamber and the spacelat the other end of said piston serving as compression chamber, and connecting pipes between the combustion chambers and the compression chambers of the cylinders of a group, whereby the two compression chambers of a group are adapted t'o communicate with one of the combustion chambers of the same group.

10. In an internal combustion engine, a plurality of closed cylinders arranged in coacting groups of two, a piston in each of said cylinders, the space at one end of a piston serving as. combustion chamber and the space at the other end of said piston serving as compression chamber, connecting pipes between the combustion chambers and the compression chambers of the cylinders of a group, and a multiw'ay cock common to said connecting pipes for connecting the two combustion chambers with one ot the said compression chambers.

11. An internal combustion engine comprisin inV combination -several cylinders arrange in pairs each cylinder being closed at both Sends, a. piston in each cylinder and dividing said cylinder into a compression space and a working space, a reservoir for compressed air, a supply pipe for the working space, a compression suction pipe and a pressure pipeV` for each cylinder, auxiliary pipes for connecting said suction and compressionpipes of the cylinders of one group, l

a reversing valve in each of said pipes, a suction pipe for the Carburettor, and a suction pipe, connecting with the atmosphere connected with each reversing valve so that, according' to the position of said reversing valves, the suction pipe of the Carburettor communicates withsuctionpipe Aof the compressorand the pressure pipe with the supply nipe for the working space or the atmosphere with the suction pipe of the compressor, the suction pipe of the carburettor with the supply pipe of the working space and the pressure pipe iwith said reservoir -for compressed air.

12. An internal combustion engine comprising in combination several c linders connected in airs each cylinder lacing closed at both en sz a piston in each cylinder dividing said cylmderK-i'ntoa working space and a compression space, a carburettor f -or each cylinder, a reservoir for compressed air for each group of two cylinders, two four-way cocks for each cylinder, a case for each four- Way cock, a compressor suction pi e connecting the compression space of the cy index` with one of said four-way cock cases, a pipe connectin the cases for the two four-Way cocks, a supi pip'e connecting the other case with the wor ing space of the cylinder, a pipe connecting said second case with said reservoir a pressure pipe of the compressor space of the cylinder and auxiliary pipes connecting said pressure pipe with said second case.

13. In an internal combustion engine, a plurality of closed cylinders, a piston 1n each cylinder, the' space at one end of the piston serving as combustion chamber, and the space at the other end of the piston serving as compression chamber, a pipe connectin the combustion chamber of one cylinder wit the compression chamber of another cylinder, means for introducing a gas into said connected compression chamber, and means for increasing the pressure ofY thefgas delivered from said connected compression chamber only for the purpose of increasing the velocity of the gas in said pipe, whereby a reduction in the size of the valves and in the extent of the valve stroke is permitted, the explosion force in'said connected com- .asf `com ression chamber, a pipe connecting the com ustion chamber' ofone c linder with thecompressionchamber ofanot er cylinder, an outlet valve for said compression chamber andan inlet valve for said combustion chamber, saidA valves being timed inV accordance with fthe length ofv pipe between said cham;

bers andthe resistance toiow in said pipe so that.' a pressure i ulsation travelling in said pipe from said out t valveto said inletvalve reaches the latter at the instant it is opened, and means for regulatingl the degree of pressure in accordance wit existin in said combustion chamber.

15. n an internal combustion engine, a plurality of closed cylinders, a iston 1n each cylinder, the space at one en of a piston serving 'as-:combustion chamber, and the spaceat the other end of said piston serving as compression' chamber, a connecting pipe between the compression chamber of one cylinder and 4the Aombustion chamber of another cylindeigga return pipe between said connectlng pipe and said compression cham` ber, and means for regulating the back iow from'said connecting `pression chamba?, said return pipe joiningl said connecting pipe at a oint near said compression/.chamber for t e' pur ose of avoidinfgdlstnrbance of the regular evelopmento i ressure .pulsations due to the oper- 4ation ofteaid regulating means.

Intestimon whereof I atiix m si nature. SVENYGUSTAF TJIND Q. ST.

the over-pressure pipe into said com- 

